1. Field of the Invention
This invention relates to an assembling apparatus employing a robot, and more particularly to an assembling apparatus which includes a plurality of assembling units having substantially the same functions and which is suitable to effect automatic assembly.
2. Description of the Related Art
Assembling robots have been and continue to be widely used to automatically assemble various electronic appliances. An exemplary, conventional assembling apparatus which employs an assembling robot is disclosed, for example, in U.S. Pat. No. 4,783,904. In the assembling apparatus, trays on which parts are arranged in a predetermined order are supplied by transport means to and stored in a stock station, and a robot selectively picks up one of the trays stored in the stock station and places the tray onto a part pickup station. Then, the robot selectively picks up one of parts, depending upon the determination of the robot, from within the tray in the part pickup station and effects automatic assembly using the thus picked up part. The robot is characterized in that it includes a plurality of horizontal, articulated robots, by which assembly of a plurality of parts is performed. The assembling apparatus, however, is disadvantageous in that, when the model of the work is to be changed, the operation program therefor cannot be changed readily and much time is required for a change of the program. It is further disadvantageous in that the horizontal, articulated robot results in low positioning accuracy.
As the needs of the market diversify, the form of production tends to change from the mass production of a single model to an average production of a plurality of models and further to a short production of a large number of models. As the size of production changes in this manner, a requirement for an assembling robot is a function of changing over the operation program therefor in a short period of time and in accordance with the model of the works so as to cope with the model. Further, as the miniaturization of electronic appliances to be assembled proceeds, a high degree of positioning accuracy is required in assembly.